In high-power drivetrain applications, such as buses and trucks, high torque is usually needed to be delivered to the wheels at relatively low speeds. In terms of powertrain electrification, this may present significant challenges in the design of an electric traction motor (also referred to as an electric machine) capable of delivering acceptable performance. A high-power electric machine designed to deliver high torque should operate with high current and flux densities. However, for electric machines operating with high current and flux densities, in typical machine designs the size of the electric machine typically increases, often significantly, and the power density may also be significantly reduced. In addition, the efficiency of the motor may fall below an acceptable level due to high copper and hysteresis losses.
Further aspects and features of the embodiments described herein will become apparent from the following detailed description taken together with the accompanying drawings. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the application, are given by way of illustration only, since various changes and modifications within the spirit and scope of the application will become apparent to those skilled in the art from this detailed description.